The increasing interest in the use of electronic media for product sales has created a need for product search strategies that are intuitive and easy to use. Most electronic catalogs provide some form of search functionality. This may be as simple as a keyword search. The search statement "find all products with the characters `MP004` in their part number descriptions" is an example of a keyword search. More complex searches, such as parametric searches, are also common. The search statement "find all products which have the parameter `color` equal to `red`" is an example of a parametric search. However, problems arise with such search methods.
Current search methods require that parameter relevance be embedded in the description of a product. This is typical in a relational database implementation, in which the database architect is forced to parameterise all notions in a product domain. For example, assume the notion of color is relevant to all computer products in a database. A relevant notion is one that a person searching for a product will always use in order to search for the particular product desired. If the notion is not parameterised, there is no way to enforce entry of information descriptive of the notion. In the example, assume a free-form text field is provided for the description of the computer. With such a field, there is no way to ensure that each entry contains a description of the color of the computer. The notion of color must be parameterised. A separate field must be created which requires that a value be entered.
It is easy to detect parameterisation by considering the different values assigned to attributes. If the values are diametric, for example, yes/no, includes/doesn't include, available/not available, 5"/6"/no inches, then the catalog architect is using parameter values to represent relevance. By building representations of this nature, the architect is attempting to capture when a feature of a component is relevant to a product and when it is not relevant. For example, assume there are two cameras in a catalog, one with autofocus and one without. To capture the fact that this feature is relevant to only one of the cameras, the positive and negative notions of this feature must be parameterised. An attribute such as "autofocus" must be created and given the value "yes" for one camera and the value "no" for the other camera.
Encoding relevance in this manner is difficult to create and maintain. Each time a feature is represented, the catalog architect must determine values for the attribute, which represents the feature, that not only describe the actual feature, but also describe the relevance of the feature to the product.